Adjustable camshafts are sufficiently known and are used to influence valve control times. The valve control times are thereby influenced by a twisting of an inner shaft relative to an outer shaft, wherein first cams are connected to the inner shaft in a torque-proof manner and second cams are connected to the outer shaft. The valve opening times or valve closure times can be shortened or lengthened by the mutual adjustment of the first and second cams. Usually a so-called phase shifter is used for twisting the inner shaft relative to the outer shaft, the rotor of which is connected in a torque-proof manner to the inner shaft and the stator of which is connected in a torque-proof manner to the outer shaft. An axial mounting of such an adjustable camshaft is usually accomplished in his case by means of an axially fixed connection of the inner shaft to the rotor, wherein in turn the rotor of the phase shifter is mounted axially with respect to the stator of the same so that in the case of an axially fixed connection of the stator to the outer shaft, this is mounted axially against the inner shaft via the phase shifter. However, the axial mounting of the camshaft via the phase shifter requires a low-tolerance and therefore high-precision connection both of the inner shaft to the rotor of the phase shifter and also of the outer shaft to the stator of the same. Overall this therefore requires a comparatively high manufacturing precision and therefore comparatively high costs.